The study has limitations. The study didn’t look at fungi or viruses living in the throat that also make up the microbiome. 32 patients is too small a sample size to make a larger generalization about the microbiomes of all schizophrenic patients. Plus, the study only addressed the bacteria in the throat microbiome, not those living in the intestines, mouth, colon, ears, or on the skin—the researchers hope to do this in future studies. There were also lots of other variables that could have affected the microbiome population, such as whether or not the patients smoked—the researchers tried to account for this, but it’s not clear that they were fully able to do so. And researchers still don’t understand the mechanisms by which bacteria affect the brain.